MEENAKSHI SUNDARARAJAN COLLEGE OF ENGINNERING, KODAMBAKAM

M.E CONSTRUCTION ENGINEERING AND MANAGEMENT

CONSTRUCION MATERIAL MANANGEMENT

R. Shanmugapriya

311513418014

INTRODUCTION

• Materials management is a vital function for improving productivity in construction

projects.

• The management of materials should be considered at all the phases of the

construction process and throughout the construction and production periods.

• This is because poor materials management can often affect the overall construction

time, quality and budget.

• It is important for planning and controlling of materials to ensure that the right

quality and quantity of materials and installed equipment are appropriately specified

in a timely manner, obtained at a reasonable cost, and are available when needed.

Definition of Construction Material Management:

Material management is defined as planning, identification, procuring, storage,

receiving and distribution of materials. The purpose of material management is to

assure that the right materials are in the right place, in the right quantise when needed.

The responsibility of material management department for the flow of materials from

the time the materials are ordered, received, and stored until they are used in the basis

of material management.

Aim of Material Management

To get

1. The Right quality

2. Right quantity of supplies

3. At the Right time

4. At the Right place

5. For the Right cost

Objectives and Functions of Materials Management

Primary objectives can be classified as:

• Efficient materials planning

• Buying or Purchasing

• Procuring and receiving

• Storing and inventory control

• Supply and distribution of materials

• Quality assurance

Secondary Objectives of Materials Management :

• Efficient production scheduling

• To take make or buy decisions

• Prepare specifications and standization of materials

• To assist in product design and development

• Forecasting demand and quantity of materials requirements

• Quality control of materials purchased

• Material handling

• Use of value analysis and value engineering

• Developing skills of workers in materials management

• Smooth flow of materials in and out of the organization•  

Classification of Construction Material

Material Type Details Example

Bulk materials Materials that are delivered in mass and are

deposited in a container.

Sand,Gravel,Topsoil,Cement,

Concrete

Bagged materials Materials delivered in bags for ease of

handling and controlled use.

Cement

Palleted materials Bagged materials that are placed in pallets for

delivery

Cement, Doors

Packaged materials Materials that are packaged together to

prevent damage during transportation and

deterioration when they are stored.

Pipes,Tiles,Electrical Fitting

Various Construction Materials

Process of Construction Material Management

Materials Handling & Traffic Variety

.. . . .

Purchasing

Store Keeping

Inventory Control

Receiving, Inspection and Despatching

Value Analysis, Standardization and Variety Reduction

 

Disposal of Scrap and Surplus, Material Preservation

.. . . .

Material planning

1. Material Planning

• Materials planning include measuring, ordering and scheduling. It is emphasized

that planning is a very important process to increase the productivity, profit, and

assisting the time to complete the construction projects.

• The productivity of the construction project will be hanged if the material

planning process is not implemented properly.

2. Purchasing

Purchase the materials and have the services from supplier to get the support of operations as the

construction project from production to marketing, sales and logistics. For examples, a detailed material list

and co-ordination of the purchasing and order of material are significant to assuring the material will

available on construction site.

According to Ninad Shah and Manish Dave Purchasing procedure can be described as below:

• Step 1 – Material Indent

• Step 2 – Enquiry to Vendors

• Step 3 – Vendor Comparison

• Step 4 – Vendor Selection and Negotiations

• Step 5 – Purchase Order

• Step 6 – Vendor Evaluation

3.Inventory control department:

The duties of the inventory control department is to decide about the types of

ordering system, fixing the safety stock limits, fixing up the reorder level & maximum /

minimum stock level.

4.Receiving, inspection and despatching department

The responsibility of Receiving, inspection and despatching department is to

receive the materials when delivered by the suppliers. After receiving it, the quantity

and quality must be checked. Production parts and materials are checked against

blueprints and specifications. Non-production items are also reviewed. When once it is

as per the specifications given, the goods will be accepted

5. The Value Analysis and Standardization

The Value Analysis and Standardization offer greatest scope, in reducing the

materials cost. It also reduce the number of varieties and also helps in finding the

substitute for the materials at lesser cost.

6. Logistics

Logistics is a concept that stresses movement of the materials and it involve

planning, implementing, and controlling the movement and storage of all things from

raw materials to the finished f the product to meet client requirements. During

construction project, routing of the materials will affect the cost and time to complete

the construction projects.

7. Disposal of Scrap and Surplus, Material Preservation

• Stock control can categorize as a technique planned to be the cover and to ensure all materials or

equipment are available when needed.

• Stock control include raw materials, processed materials, assembly components, consumable stores,

general stores, maintenance materials and spares, work in progress and finished products.

• It is very important as the construction materials were delivery as requested and with the progression

by the proper management of stock control.

• At the same time, construction activities will generate big amount of the waste and it will cause

difficulty to the construction industry.

• However, with the planning of the material management which is effective will help to reduce the

waste of material and increase the profit of the companies.

Problems of Material Management

1. Organization Structure

The coordination and communication between estimating department, research and development department,

purchasing department, and plant and machineries department should be maintained at highest level

Main issues in organisation structure:

• Undefined scope

• Lack of communication between parties involved

• Incomplete drawings Plans are not completed and details are missing

• Lack of conformance to requirements

• Nonstandard specifications that are not commonly used

• Incomplete / ineffective meetings

• Difference between plans and specifications

• Don’t communicate exactly

2. Procurement problem

• Availability of material

• Availability of quantity

• Price reduction to match competitor’s price

• Late deliveries Materials are not delivered as per schedule

• Late or incorrect submittals

• Poor communication between parties

• Lack of conformance to requirements

• Unrealistic delivery dates

• Re handling of materials

• Storage areas are limited or are far from working area

• Theft or damaging during handling or other conditions

3. Storage Space

• Large number of materials is required depending on the magnitude of the project.

• And the term storage space implies both enclosed and open space that can be used to keep materials

of work safe until the need for it arise.

• All materials need protection against many threats such as pilferage, theft, damage or loss. Material

such as aggregates, bricks/blocks may not require enclosed storage protection than proper outdoor

positioning and stacking. However, other materials such as reinforcement bars, steel columns, timber,

and galvanized steel for trusses must be protected against contact with water in order to avoid

rust/corrosion.

• The size of proposed building may occupy 60% of the total project site, enabling the remaining 40%

to be used for temporary access and site facilities. In such case, the planners must arrange for

periodic delivery of certain materials to avoid cluttering the space, and maintain constant operation to

keep the surrounding area clean.

4. Security Problem

Security of materials onsite is of paramount importance. Gradual pilferage

and theft are issues of concern to the project managers. Loss of materials

through pilferage and theft represent financial lost to the project as a whole,

and in the end it increases the cost of the project. Materials are prone to be

stolen despite being in store. And some materials as earlier mentioned may

not require indoor storage. Therefore, a well designated vigilante must be

maintained 24 hours onsite.

5. Availability of Materials on Market

• Steady flow of materials throughout project duration is among the primary

function of material management. However, this can be affected by market

availability of the material of work.

• Occasionally manufacturers can run out of raw material or be affected by

government policy to the extent that production may have to be slow or

suspended. Unavailability of materials of work on market can affect

material management by either increasing competition in material purchase

or delay the general work progress.

Importance of Materials Management

• Lower prices for material and equipment.

• Faster inventory turnover.

• Continuity of supply

• Reduced lead time

• Reduced transportation cost.

• Less duplication of efforts.

• Elimination of bulk- passing.

• Reduced materials obsolescence.

• Improved supplier relationship and better records and information.

• Better inter-department cooperation & Personnel development

Advantages of Materials Management

• The better accountability part of the material, as well as other

departments and no one can blame others.

• As materials management by a single authority, which can lead to better

coordination, because it became the central point of any substance-related

problems.

• Materials management departments to ensure a better quality materials

provide a request in a timely fashion department. This can lead to a better

performance of the organization.

• A materials management system is usually controlled through a system,

therefore, can help decision-making related to the material in the organization.

• An indirect use of materials management is the development of good quality

material, ethical and moral standards in an organization.

• Maximum company profit and Improvement of credibility

• Improved customer service

• Enhancement of communication

• Improved quality of staff

Inventory Control for Quantitative Analysis

Definition:

Inventory control can be defined as, “which ensures the supply of

required quantity and quality of inventory at the required time and at the

same time prevent unnecessary investment in inventories”

Objectives of Inventory Control

• To ensure that the supply of raw material & finished goods will remain continuous

so that production process is not halted and demands of customers are duly met.

• To minimise carrying cost of inventory.

• To keep investment in inventory at optimum level.

• To reduce the losses of theft, obsolescence & wastage etc.

• To make arrangement for sale of slow moving items.

• To minimise inventory ordering cost.

Main Techniques in Inventory Control

The Pareto principle states that 80% of the overall consumption value is

based on only 20% of total items. In other words, demand is not evenly

distributed between items: top sellers vastly outperform the rest. The

ABC approach states that, when reviewing inventory, a company should

rate items from A to C, basing its ratings on the following rules:

1.ABC Analysis

The ABC (Always Better Control) inventory control technique is based on the

principle that a small portion of the items may typically represent the bulk of money

value of the total inventory in construction process, while a relatively large number

of items may from a small part of the money value of stores. The money value is

ascertained by multiplying the quantity of material of each item by its unit price.

Procedure for ABC Analysis

• Make the list of all items of inventory.

• Determine the annual volume of usage & money value of each item.

• Multiply each item’s annual volume by its rupee value. 

• Compute each item’s percentage of the total inventory in terms of annual usage in rupees

• “A” Category – 5% to 10% of the items represent 70% to 75% of the money value.

• “B” Category – 15% to 20% of the items represent 15% to 20% of the money.

• “C” Category – The remaining number of the items represent 5% to 10% of the money value.

• The relative position of these items show that items of category A should be under the

maximum control, items of category B may not be given that much attention and item C may

be under a loose control.

EOQ analysis

The EOQ refers to the order size that will result in the lowest total of ordering and

carrying costs for an item of inventory. If a firm place unnecessary orders it will

incur unneeded order costs. If a firm places too few order, it must maintain large

stocks of goods and will have excessive carrying cost.

Technologies in construction Material Management

The tools used in the construction industry change constantly with the

continuous changes of technology. Researchers are finding ways to

apply those changes in technology to construction in order to improve

production and lower the cost of the operations.

• Bar Codes Applications to Material Management

• RFID-Radio Frequency Identification

 1.Bar Codes Applications to Material Management

Bar code applications in construction are mostly intended to provide accuracy in data

collection, to improve productivity and to save time in the data collection process.

• Typically, bar codes are used for materials and inventory management.

The scope of bar codes extends beyond materials management.

• Bar codes provide the advantage of relatively error free data collection, which

improves productivity and avoid errors.

• Some construction firms that use bar codes claim that it saves time, money and

labor while improving the accuracy of inventory.

The major applications of bar code to material management identified in previous research can be identified as follow

• Field material control

• Warehouse maintenance and control

• Inventory control applications and tool and consumable material issue

• Purchasing and accounting

2. RFID-Radio Frequency Identification

A Radio Frequency Identification (RFID) system is an automated data collection system similar to

bar code. RFID applications in construction are mostly intended to provide accuracy in data

collection, to improve productivity and to save time in the data collection process.

An ADC (Automated Data Collection) technology that:

• uses radiofrequency waves to transfer data between a reader and a movable item to identify,

categorize,track..

• Is fast and does not require physical sight or contact between reader/scanner and the tagged item.

• Performs the operation using low cost components.

• Attempts to provide unique identification and backend integration that allows for wide range of

applications.

How RFID Works:

There are two primary components of an RFID system as shown in Figure The whole RFID system requires the tags and the reader including an antenna to be operated

Details of RFID System Components

RFID Components Details

Tags Tags or transponder are normally located on the object or people

to be identified.

Reader Reader interrogator provides, read and write/read facilities

through a fixed or mobile reader to communicate data to and

from the tags.

Antenna Antenna is the conductive element that enables the tag to send

and receive data

Passive RFID Tags

Passive RFID Tag

• Generally, passive tags have shorter read ranges of a few inches to 30 feet, but

have a long life than active tags.

• The passive RFID tags consist of a microchip attached to an antenna and can be

packaged in a different way such as mounted on a substrate to create a tag,

sandwiched between an adhesive layer and a paper label to create a printable

RFID label (or smart label), embedded in a plastic card, a key fob, the wall of a

plastic container, and special packaging (to resist heat, cold or harsh cleaning

chemicals)

• Do not require power – Draws from Interrogator Field

• Lower storage capacities (few bits to 1 KB)

• Shorter read ranges (4 inches to 15 feet)

• Usually WriteOnceReadMany/ReadOnly tags

Active RFID Tags:

• Active RFID tags have their own internal power supply and are rewritable.

• The features of the active tags are much larger and heavier, and more expensive, but have a better

noise protection than passive tags.

• However, they have a shorter battery life of up to 10 years, with read range of 60 feet to 300 feet

(20 metres to 100 metres).

• The example of the active RFID tags can be shown in Figure 5. Active tags are more reliable in

environments such as water (including human/cattle, which are mostly water), metal (shipping

containers, vehicles), or at longer distances for generating strong responses from weak requests.

• They also have larger memories than passive tags and the ability to store additional information

sent by the transceiver

• Some RFID Tags

RFID READER

Uses of RFID:

RFID had been used for material tracking and material receipt in the construction

industry.

• Material Tracking: Material as the move in the jobsite since direct contact is not

required for data collection. This can avoid theft and lost since managers can

notice when materials are not where they are supposed to be.

• Materials Receipt: Materials can be easily verified as they arrive to the site. The

type of materials received can be known easily and verify if the right quantities

were received.

RFID Applications

• Manufacturing and Processingo Inventory and production process monitoringoWarehouse order fulfilment

• Supply Chain Managemento Inventory tracking systemsoLogistics management

• Retailo Inventory control and customer insightoAuto checkout with reverse logistics

• SecurityoAccess controloCounterfeiting and Theft control/prevention

• Location TrackingoTraffic movement control and parking management

RFID Application points

RFID advantages over barcodes

• No line of sight required for reading

• Multiple items can be read with a single scan

• Each tag can carry a lot of data (read/write)

• Individual items identified and not just the category

• Passive tags have a virtually unlimited lifetime

• Active tags can be read from great distances

• Can be combined with barcode technology

Conclusion

This paper has presented a review of Construction material management ,Inventory control and employment of technology in construction projects.

• Good planning of materials management can help to avoid any delays of works on site and reduce any extra

cost for a project.

• It is important to manage all materials and inventory throughout construction activity and processes

• It discussed the materials management on construction projects and potential to employ RFID in materials

management practices.

• It clearly identified that these are important for effectively managing materials management in the

construction project in order to provide better handling of construction materials to provide an overall

performance of construction projects in term of time, budget (cost) and quality.